title: Circulating levels of human salusin-β, a potent hemodynamic and atherogenesis regulator.
abstract: Using bioinformatics analysis, we previously identified salusin-β, an endogenous bioactive peptide with diverse physiological activities. Salusin-β is abundantly expressed in the neuroendocrine system and in systemic endocrine cells/macrophages. Salusin-β acutely regulates hemodynamics and chronically induces atherosclerosis, but its unique physicochemical characteristics to tightly adhere to all types of plastic and glassware have prevented elucidation of its precise pathophysiological role. To quantitate plasma total salusin-β concentrations, we produced rabbit and chicken polyclonal antibodies against the C- and N-terminal end sequences, circumvented its sticky nature, and successfully established a sandwich enzyme-linked immunosorbent assay (ELISA). Salusin-β was abundantly present in the plasma of healthy volunteers, ranging from 1.9 to 6.6 nmol/L. Reverse phase-high performance liquid chromatography analysis showed that a single immunoreactive salusin-β peak coincided with synthetic authentic salusin-β. Plasma salusin-β concentrations were unaffected by postural changes and by potent vasopressin release stimuli, such as hypertonic saline infusion or smoking. However, salusin-β concentrations showed significant circadian variation; concentrations were high during the daytime and reached the lowest concentrations in the early morning. Plasma salusin-β levels in subjects with diabetes mellitus, coronary artery disease, and cerebrovascular disease showed distinctly higher levels than healthy controls. Patients with panhypopituitarism combined with complete central diabetes insipidus also showed significantly higher plasma salusin-β levels. Therefore, the ELISA system developed in this study will be useful for evaluating circulating total salusin-β levels and for confirming the presence of authentic salusin-β in human plasma. The obtained results suggest a limited contribution of the neuroendocrine system to peripheral total salusin-β concentrations and a role for plasma total salusin-β concentrations as an indicator of systemic vascular diseases.
authors.affiliation: Laboratory of Molecular Genetics of Hematology, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo, Japan ; Department of Endocrinology, Diabetes and Metabolism, Kitasato University School of Medicine, Kanagawa, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Fujimoto
authors.forename: Akinori
authors.initials: A
authors.lastname: Hayashi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kamata
authors.forename: Akifumi
authors.initials: A
authors.lastname: Ogawa
authors.forename: Takuya
authors.initials: T
authors.lastname: Watanabe
authors.forename: Raishi
authors.initials: R
authors.lastname: Ichikawa
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Iso
authors.forename: Shinji
authors.initials: S
authors.lastname: Koba
authors.forename: Youichi
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Koyama
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Shichiri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000906:Antibodies / Q000097:blood / Q000737:chemistry; D050197:Atherosclerosis / Q000097:blood* / Q000503:physiopathology; D002561:Cerebrovascular Disorders / Q000097:blood / Q000503:physiopathology; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D002940:Circadian Rhythm / Q000502:physiology; D003324:Coronary Artery Disease / Q000097:blood / Q000503:physiopathology; D003920:Diabetes Mellitus / Q000097:blood / Q000503:physiopathology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007018:Hypopituitarism / Q000097:blood / Q000503:physiopathology; D036341:Intercellular Signaling Peptides and Proteins / Q000302:isolation & purification* / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D012016:Reference Values
chemical_list: D000906:Antibodies; D036341:Intercellular Signaling Peptides and Proteins; C478739:TOR2A protein, human